We could do so much good with excess power generation if we wanted to. We could produce hydrogen. We could electrolyse CO2 out of the air. We could filter the plastic out of ocean water. We could analyse space radiation. We could run recycling plants. We could flood the bitcoin market. We could run a desalination plant. Why does this have to be a problem?
So why was the problem expressed in economic terms? The practical problem isn't "oh noes there's a price label with a minus on it"; it's that there's a surplus of power which is dangerous.
In reality what that represents is an opportunity for someone to come in, and store the excess power, and sell it back to the grid when supply is lower -- but energy companies only want to model the flow of money going one way.
Sigh... *unzips